The Life of the Mind

To celebrate the end of the year at Mind Matters, we’re going to highlight a few of the posts that we featured over the past 12 months. Although our articles have covered a wide variety of subjects, from visual illusions to borderline personality disorder to the limitations of free will, many of our most popular posts dealt with the intersection of neuroscience and everyday life.

This fact is, perhaps, a testament to the increasing relevance of neuroscience and psychology to society. As scientists break open the black box of the mind, and begin to unravel the neural processes that define our behavior, it’s becoming clear that who we are—and what we decide to do—is ultimately shaped by the quirks and constraints of these three pounds of flesh inside the head.

Consider a September Mind Matters article on how the brain responds to calories, and why it can so hard to stop eating even when we’re no longer hungry. The article summarized a recent experiment in which a strain of mice was created that was missing the taste receptor for sweetness. As a result, these mice demonstrated no preference for sugar water, unlike control mice. Something interesting happened when the mutant mice were given sugar water for six straight days, however: they learned to like it, even if they couldn’t taste it. As the scientists note in their Mind Matters post, “There seems to be something inherently pleasurable about ingesting food that contains calories.” This result helps explain why we keep on stuffing our face even when we’re sated and the food isn’t particularly delicious—the brain just likes the taste of energy.

Mind Matters also featured several articles on the neuroscience of politics, which was fitting given the heated presidential campaign. An October interview with Sheldon Solomon, a professor of psychology at Skidmore College, looked at why thinking about death makes people more conservative. This notion is known as Terror Management Theory, and it plays an important role, Solomon argues, in how people vote during times of war.
We also talked with the neurologist Robert Burton, who had some important advice for president-elect Barack Obama: don’t fall into the certainty trap! Burton argues that the feelings generated by beliefs can be just as powerful as the feelings generated by addictive drugs or chocolate cake, which is why it can be so tempting to believe that our beliefs are true. In other words, we are designed to crave certainty, just like a smoker craves nicotine. Burton also told a poignant story about what happens when our desire to be certain overwhelms our ability to distinguish between truth and fiction:

One of my favorite examples of how certainty is often misleading is the great mathematician Srinivasava Ramanujan. At his death, his notebook was filled with theorems that he was certain were correct. Some were subsequently proven correct; others turned out to be dead wrong. Ramanujan’s lines of reasoning lead to correct and incorrect answers, but he couldn’t tell the difference.

We also looked at how behavior is generated by the brain at a more detailed level. An August article, by John Pearson and Michael Platt of Duke University, reviewed an experiment that “eavesdropped” on the neural circuitry involved in decision-making. The scientists simultaneously recorded from neurons in the frontal cortex and parietal cortex, allowing them to monitor the electrical conversation between these different brain areas. They found that when monkeys are required to make a decision—and aren’t just acting based on a learned reflex—these cortical regions are engaged in an elaborate dialogue, as the monkey contemplated its options. The larger implication of such research, according to Pearson and Platt, is that it’s misleading to think of decisions in terms of localized brain areas or a discrete collection of cells. Instead, every choice we make depends on the crosstalk between circuits located all over the cortex.

A July article by the neuroscientist Mauricio Delgado, at Rutgers University, examined an intriguing experiment that investigated the effects of oxytocin, a hormone involved in social attachment. (Oxytocin is released in large quantities into the bloodstream during childbirth.) The scientists had subjects play a simple “trust game,” in which they can make more money by temporarily entrusting their money to another person. Although this behavior can be lucrative, it’s also risky, because the “trustee” can always abscond with the cash and betray the original investor. (This experiment is especially relevant in the wake of the Bernard Madoff scandal.) The scientists found that subjects given puffs of oxytocin via a nasal spray didn’t become less likely to trust another person after their trust had been violated. In contrast, control subjects given a placebo became much less likely to trust another person after being betrayed. This finding suggests that a single hormone can profoundly influence our social interactions. The scientists caution, however, that their results are preliminary, and that we shouldn’t rush out and waste money on an oxytocin nasal spray. After all, sometimes it’s good to be wary—just ask investors who lost their money to Madoff.

What subjects will neuroscience illuminate in 2009? Are there any scientific ideas you’d like to see us cover or pay more attention to? Send a note to Jonah Lehrer. Thanks for reading, and we look forward to another exciting year of Mind Matters.

Scientific American is part of Springer Nature, which owns or has commercial relations with thousands of scientific publications (many of them can be found at www.springernature.com/us). Scientific American maintains a strict policy of editorial independence in reporting developments in science to our readers.